Translation services tend to fall into one of three categories:
On the surface, the advantage of the latter two options is that they're "free". As we'll discuss below, though:
Free machine translations have the advantage of being practically instant and costing practically no money. I say "practically" because you may find that it takes one or two attempts, correcting spelling and punctuation, for your text to be recognised and translated in any way adequately. If you simply don't have the resources to get your text properly translated by a human, then MT systems can be a godsend when a very rough translation is better than no translation at all.
So when should you opt for a human translation?
Well, remember when you created the original copy for your web site, for example, you probably thought carefully about what wording would help you sell your product. You were so concerned that your text would sound appealing, that you maybe even contracted a marketing company specially. Or when you put together that Powerpoint presentation, you probably put some thought into how to explain the material most effectively, so that your employees would understand it first time, and thus not waste time later on needing it to be re-explained.
Well, guess what... these kinds of criteria don't suddenly go out of the window just because your text is in another language!
A good human translator will be continually trying to gain the best understanding and appreciation of your text, understand the purpose of that text, and choose the best translation to meet those objectives. The same criteria that you had when you wrote or comissioned the original text— be it clarity, conciseness, "catchiness", "political correctness" etc— are the criteria that a good translator will be able to apply when working on your text. A good translator or team of translators is not applying a mechanical process. They are using their years of professional writing experience to work with you to make your text achieve its purpose. They can act as a mini "marketing department" helping you sell your products to your foreign customers. Or they can help you explain your training material so that your employees "get it" first time.
Another point to consider is simply that the translation is probably the initial point of contact that your customers have with your company, that the readers of your book have with your work etc. A shoddy translation gives a shoddy impression.
So against the cost of translation, you have to offset the extra revenue that a good translation may generate because it makes your company look more credible, or the time that your employees save by not having to find and read extra material to replace the poor translation that didn't meet their needs first time round.
Book translation tips
Machine translation service